// Copyright (C) 1998-2001 by Jason Hunter <jhunter_AT_acm_DOT_org>.
// All rights reserved.  Use of this class is limited.
// Please see the LICENSE for more information.

package com.baomidou.framework.upload.cos;

import java.io.File;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpUtils;

import com.baomidou.framework.upload.cos.multipart.FilePart;
import com.baomidou.framework.upload.cos.multipart.FileRenamePolicy;
import com.baomidou.framework.upload.cos.multipart.MultipartParser;
import com.baomidou.framework.upload.cos.multipart.ParamPart;
import com.baomidou.framework.upload.cos.multipart.Part;

/**
 * A utility class to handle <code>multipart/form-data</code> requests, the kind
 * of requests that support file uploads. This class emulates the interface of
 * <code>HttpServletRequest</code>, making it familiar to use. It uses a "push"
 * model where any incoming files are read and saved directly to disk in the
 * constructor. If you wish to have more flexibility, e.g. write the files to a
 * database, use the "pull" model <code>MultipartParser</code> instead.
 * <p>
 * This class can receive arbitrarily large files (up to an artificial limit you
 * can set), and fairly efficiently too. It cannot handle nested data (multipart
 * content within multipart content). It <b>can</b> now with the latest release
 * handle internationalized content (such as non Latin-1 filenames).
 * <p>
 * To avoid collisions and have fine control over file placement, there's a
 * constructor variety that takes a pluggable FileRenamePolicy implementation. A
 * particular policy can choose to rename or change the location of the file
 * before it's written.
 * <p>
 * See the included upload.war for an example of how to use this class.
 * <p>
 * The full file upload specification is contained in experimental RFC 1867,
 * available at
 * <a href="http://www.ietf.org/rfc/rfc1867.txt"> http://www.ietf.org/rfc/
 * rfc1867.txt</a>.
 *
 * @see MultipartParser
 * 
 * @author Jason Hunter
 * @author Geoff Soutter
 * @version 1.12, 2004/04/11, added null check for Opera malformed bug<br>
 * @version 1.11, 2002/11/01, combine query string params in param list<br>
 * @version 1.10, 2002/05/27, added access to the original file names<br>
 * @version 1.9, 2002/04/30, added support for file renaming, thanks to
 *          Changshin Lee<br>
 * @version 1.8, 2002/04/30, added support for internationalization, thanks to
 *          Changshin Lee<br>
 * @version 1.7, 2001/02/07, made fields protected to increase user flexibility
 *          <br>
 * @version 1.6, 2000/07/21, redid internals to use MultipartParser, thanks to
 *          Geoff Soutter<br>
 * @version 1.5, 2000/02/04, added auto MacBinary decoding for IE on Mac<br>
 * @version 1.4, 2000/01/05, added getParameterValues(), WebSphere 2.x
 *          getContentType() workaround, stopped writing empty "unknown" file
 *          <br>
 * @version 1.3, 1999/12/28, IE4 on Win98 lastIndexOf("boundary=") workaround
 *          <br>
 * @version 1.2, 1999/12/20, IE4 on Mac readNextPart() workaround<br>
 * @version 1.1, 1999/01/15, JSDK readLine() bug workaround<br>
 * @version 1.0, 1998/09/18<br>
 */
public class MultipartRequest {

	private static final int DEFAULT_MAX_POST_SIZE = 1024 * 1024; // 1 Meg

	protected Hashtable parameters = new Hashtable(); // name - Vector of values
	protected Hashtable files = new Hashtable(); // name - UploadedFile

	/**
	 * Constructs a new MultipartRequest to handle the specified request, saving
	 * any uploaded files to the given directory, and limiting the upload size
	 * to 1 Megabyte. If the content is too large, an IOException is thrown.
	 * This constructor actually parses the <tt>multipart/form-data</tt> and
	 * throws an IOException if there's any problem reading or parsing the
	 * request.
	 *
	 * @param request
	 *            the servlet request.
	 * @param saveDirectory
	 *            the directory in which to save any uploaded files.
	 * @exception IOException
	 *                if the uploaded content is larger than 1 Megabyte or
	 *                there's a problem reading or parsing the request.
	 */
	public MultipartRequest(HttpServletRequest request, String saveDirectory) throws IOException {
		this(request, saveDirectory, DEFAULT_MAX_POST_SIZE);
	}

	/**
	 * Constructs a new MultipartRequest to handle the specified request, saving
	 * any uploaded files to the given directory, and limiting the upload size
	 * to the specified length. If the content is too large, an IOException is
	 * thrown. This constructor actually parses the <tt>multipart/form-data</tt>
	 * and throws an IOException if there's any problem reading or parsing the
	 * request.
	 *
	 * @param request
	 *            the servlet request.
	 * @param saveDirectory
	 *            the directory in which to save any uploaded files.
	 * @param maxPostSize
	 *            the maximum size of the POST content.
	 * @exception IOException
	 *                if the uploaded content is larger than
	 *                <tt>maxPostSize</tt> or there's a problem reading or
	 *                parsing the request.
	 */
	public MultipartRequest(HttpServletRequest request, String saveDirectory, int maxPostSize) throws IOException {
		this(request, saveDirectory, maxPostSize, null, null);
	}

	/**
	 * Constructs a new MultipartRequest to handle the specified request, saving
	 * any uploaded files to the given directory, and limiting the upload size
	 * to the specified length. If the content is too large, an IOException is
	 * thrown. This constructor actually parses the <tt>multipart/form-data</tt>
	 * and throws an IOException if there's any problem reading or parsing the
	 * request.
	 *
	 * @param request
	 *            the servlet request.
	 * @param saveDirectory
	 *            the directory in which to save any uploaded files.
	 * @param encoding
	 *            the encoding of the response, such as ISO-8859-1
	 * @exception IOException
	 *                if the uploaded content is larger than 1 Megabyte or
	 *                there's a problem reading or parsing the request.
	 */
	public MultipartRequest(HttpServletRequest request, String saveDirectory, String encoding) throws IOException {
		this(request, saveDirectory, DEFAULT_MAX_POST_SIZE, encoding, null);
	}

	/**
	 * Constructs a new MultipartRequest to handle the specified request, saving
	 * any uploaded files to the given directory, and limiting the upload size
	 * to the specified length. If the content is too large, an IOException is
	 * thrown. This constructor actually parses the <tt>multipart/form-data</tt>
	 * and throws an IOException if there's any problem reading or parsing the
	 * request.
	 *
	 * @param request
	 *            the servlet request.
	 * @param saveDirectory
	 *            the directory in which to save any uploaded files.
	 * @param maxPostSize
	 *            the maximum size of the POST content.
	 * @param policy
	 *            the rules for renaming in case of file name collisions
	 * @exception IOException
	 *                if the uploaded content is larger than
	 *                <tt>maxPostSize</tt> or there's a problem reading or
	 *                parsing the request.
	 */
	public MultipartRequest(HttpServletRequest request, String saveDirectory, int maxPostSize, FileRenamePolicy policy)
			throws IOException {
		this(request, saveDirectory, maxPostSize, null, policy);
	}

	/**
	 * Constructs a new MultipartRequest to handle the specified request, saving
	 * any uploaded files to the given directory, and limiting the upload size
	 * to the specified length. If the content is too large, an IOException is
	 * thrown. This constructor actually parses the <tt>multipart/form-data</tt>
	 * and throws an IOException if there's any problem reading or parsing the
	 * request.
	 *
	 * @param request
	 *            the servlet request.
	 * @param saveDirectory
	 *            the directory in which to save any uploaded files.
	 * @param maxPostSize
	 *            the maximum size of the POST content.
	 * @param encoding
	 *            the encoding of the response, such as ISO-8859-1
	 * @exception IOException
	 *                if the uploaded content is larger than
	 *                <tt>maxPostSize</tt> or there's a problem reading or
	 *                parsing the request.
	 */
	public MultipartRequest(HttpServletRequest request, String saveDirectory, int maxPostSize, String encoding)
			throws IOException {
		this(request, saveDirectory, maxPostSize, encoding, null);
	}

	/**
	 * Constructs a new MultipartRequest to handle the specified request, saving
	 * any uploaded files to the given directory, and limiting the upload size
	 * to the specified length. If the content is too large, an IOException is
	 * thrown. This constructor actually parses the <tt>multipart/form-data</tt>
	 * and throws an IOException if there's any problem reading or parsing the
	 * request.
	 *
	 * To avoid file collisions, this constructor takes an implementation of the
	 * FileRenamePolicy interface to allow a pluggable rename policy.
	 *
	 * @param request
	 *            the servlet request.
	 * @param saveDirectory
	 *            the directory in which to save any uploaded files.
	 * @param maxPostSize
	 *            the maximum size of the POST content.
	 * @param encoding
	 *            the encoding of the response, such as ISO-8859-1
	 * @param policy
	 *            a pluggable file rename policy
	 * @exception IOException
	 *                if the uploaded content is larger than
	 *                <tt>maxPostSize</tt> or there's a problem reading or
	 *                parsing the request.
	 */
	public MultipartRequest(HttpServletRequest request, String saveDirectory, int maxPostSize, String encoding,
			FileRenamePolicy policy) throws IOException {
		// Sanity check values
		if (request == null)
			throw new IllegalArgumentException("request cannot be null");
		if (saveDirectory == null)
			throw new IllegalArgumentException("saveDirectory cannot be null");
		if (maxPostSize <= 0) {
			throw new IllegalArgumentException("maxPostSize must be positive");
		}

		// Save the dir
		File dir = new File(saveDirectory);

		// Check saveDirectory is truly a directory
		if (!dir.isDirectory())
			throw new IllegalArgumentException("Not a directory: " + saveDirectory);

		// Check saveDirectory is writable
		if (!dir.canWrite())
			throw new IllegalArgumentException("Not writable: " + saveDirectory);

		// Parse the incoming multipart, storing files in the dir provided,
		// and populate the meta objects which describe what we found
		MultipartParser parser = new MultipartParser(request, maxPostSize, true, true, encoding);

		// Some people like to fetch query string parameters from
		// MultipartRequest, so here we make that possible. Thanks to
		// Ben Johnson, ben.johnson@merrillcorp.com, for the idea.
		if (request.getQueryString() != null) {
			// Let HttpUtils create a name->String[] structure
			Hashtable queryParameters = HttpUtils.parseQueryString(request.getQueryString());
			// For our own use, name it a name->Vector structure
			Enumeration queryParameterNames = queryParameters.keys();
			while (queryParameterNames.hasMoreElements()) {
				Object paramName = queryParameterNames.nextElement();
				String[] values = (String[]) queryParameters.get(paramName);
				Vector newValues = new Vector();
				for (int i = 0; i < values.length; i++) {
					newValues.add(values[i]);
				}
				parameters.put(paramName, newValues);
			}
		}

		Part part;
		while ((part = parser.readNextPart()) != null) {
			String name = part.getName();
			if (name == null) {
				throw new IOException("Malformed input: parameter name missing (known Opera 7 bug)");
			}
			if (part.isParam()) {
				// It's a parameter part, add it to the vector of values
				ParamPart paramPart = (ParamPart) part;
				String value = paramPart.getStringValue();
				Vector existingValues = (Vector) parameters.get(name);
				if (existingValues == null) {
					existingValues = new Vector();
					parameters.put(name, existingValues);
				}
				existingValues.addElement(value);
			} else if (part.isFile()) {
				// It's a file part
				FilePart filePart = (FilePart) part;
				String fileName = filePart.getFileName();
				if (fileName != null) {
					filePart.setRenamePolicy(policy); // null policy is OK
					// The part actually contained a file
					filePart.writeTo(dir);
					files.put(name, new UploadedFile(dir.toString(), filePart.getFileName(), fileName,
							filePart.getContentType()));
				} else {
					// The field did not contain a file
					files.put(name, new UploadedFile(null, null, null, null));
				}
			}
		}
	}

	/**
	 * Constructor with an old signature, kept for backward compatibility.
	 * Without this constructor, a servlet compiled against a previous version
	 * of this class (pre 1.4) would have to be recompiled to link with this
	 * version. This constructor supports the linking via the old signature.
	 * Callers must simply be careful to pass in an HttpServletRequest.
	 * 
	 */
	public MultipartRequest(ServletRequest request, String saveDirectory) throws IOException {
		this((HttpServletRequest) request, saveDirectory);
	}

	/**
	 * Constructor with an old signature, kept for backward compatibility.
	 * Without this constructor, a servlet compiled against a previous version
	 * of this class (pre 1.4) would have to be recompiled to link with this
	 * version. This constructor supports the linking via the old signature.
	 * Callers must simply be careful to pass in an HttpServletRequest.
	 * 
	 */
	public MultipartRequest(ServletRequest request, String saveDirectory, int maxPostSize) throws IOException {
		this((HttpServletRequest) request, saveDirectory, maxPostSize);
	}

	/**
	 * Returns the names of all the parameters as an Enumeration of Strings. It
	 * returns an empty Enumeration if there are no parameters.
	 *
	 * @return the names of all the parameters as an Enumeration of Strings.
	 */
	public Enumeration getParameterNames() {
		return parameters.keys();
	}

	/**
	 * Returns the names of all the uploaded files as an Enumeration of Strings.
	 * It returns an empty Enumeration if there are no file input fields on the
	 * form. Any file input field that's left empty will result in a FilePart
	 * with null contents. Each file name is the name specified by the form, not
	 * by the user.
	 *
	 * @return the names of all the uploaded files as an Enumeration of Strings.
	 */
	public Enumeration getFileNames() {
		return files.keys();
	}

	/**
	 * Returns the value of the named parameter as a String, or null if the
	 * parameter was not sent or was sent without a value. The value is
	 * guaranteed to be in its normal, decoded form. If the parameter has
	 * multiple values, only the last one is returned (for backward
	 * compatibility). For parameters with multiple values, it's possible the
	 * last "value" may be null.
	 *
	 * @param name
	 *            the parameter name.
	 * @return the parameter value.
	 */
	public String getParameter(String name) {
		try {
			Vector values = (Vector) parameters.get(name);
			if (values == null || values.size() == 0) {
				return null;
			}
			String value = (String) values.elementAt(values.size() - 1);
			return value;
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * Returns the values of the named parameter as a String array, or null if
	 * the parameter was not sent. The array has one entry for each parameter
	 * field sent. If any field was sent without a value that entry is stored in
	 * the array as a null. The values are guaranteed to be in their normal,
	 * decoded form. A single value is returned as a one-element array.
	 *
	 * @param name
	 *            the parameter name.
	 * @return the parameter values.
	 */
	public String[] getParameterValues(String name) {
		try {
			Vector values = (Vector) parameters.get(name);
			if (values == null || values.size() == 0) {
				return null;
			}
			String[] valuesArray = new String[values.size()];
			values.copyInto(valuesArray);
			return valuesArray;
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * Returns the filesystem name of the specified file, or null if the file
	 * was not included in the upload. A filesystem name is the name specified
	 * by the user. It is also the name under which the file is actually saved.
	 *
	 * @param name
	 *            the html page's file parameter name.
	 * @return the filesystem name of the file.
	 */
	public String getFilesystemName(String name) {
		try {
			UploadedFile file = (UploadedFile) files.get(name);
			return file.getFilesystemName(); // may be null
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * Returns the original filesystem name of the specified file (before any
	 * renaming policy was applied), or null if the file was not included in the
	 * upload. A filesystem name is the name specified by the user.
	 *
	 * @param name
	 *            the html page's file parameter name.
	 * @return the original file name of the file.
	 */
	public String getOriginalFileName(String name) {
		try {
			UploadedFile file = (UploadedFile) files.get(name);
			return file.getOriginalFileName(); // may be null
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * Returns the content type of the specified file (as supplied by the client
	 * browser), or null if the file was not included in the upload.
	 *
	 * @param name
	 *            the html page's file parameter name.
	 * @return the content type of the file.
	 */
	public String getContentType(String name) {
		try {
			UploadedFile file = (UploadedFile) files.get(name);
			return file.getContentType(); // may be null
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * Returns a File object for the specified file saved on the server's
	 * filesystem, or null if the file was not included in the upload.
	 *
	 * @param name
	 *            the html page's file parameter name.
	 * @return a File object for the named file.
	 */
	public File getFile(String name) {
		try {
			UploadedFile file = (UploadedFile) files.get(name);
			return file.getFile(); // may be null
		} catch (Exception e) {
			return null;
		}
	}
}

// A class to hold information about an uploaded file.
//
class UploadedFile {

	private String dir;
	private String filename;
	private String original;
	private String type;

	UploadedFile(String dir, String filename, String original, String type) {
		this.dir = dir;
		this.filename = filename;
		this.original = original;
		this.type = type;
	}

	public String getContentType() {
		return type;
	}

	public String getFilesystemName() {
		return filename;
	}

	public String getOriginalFileName() {
		return original;
	}

	public File getFile() {
		if (dir == null || filename == null) {
			return null;
		} else {
			return new File(dir + File.separator + filename);
		}
	}
}
